Delete left-over using declaration.

webrtc/call/call.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 108 matching lines @@
 
   void OnTransportOverheadChanged(MediaType media,
                                   int transport_overhead_per_packet) override;
 
   void OnNetworkRouteChanged(const std::string& transport_name,
                              const rtc::NetworkRoute& network_route) override;
 
   void OnSentPacket(const rtc::SentPacket& sent_packet) override;
 
 
-  // TODO(minyue): remove this when old OnNetworkChanged is deprecated. See
-  // https://bugs.chromium.org/p/webrtc/issues/detail?id=6796
-  using CongestionController::Observer::OnNetworkChanged;
-
   // Implements BitrateObserver.
   void OnNetworkChanged(uint32_t bitrate_bps,
                         uint8_t fraction_loss,
                         int64_t rtt_ms,
                         int64_t probing_interval_ms) override;
 
   // Implements BitrateAllocator::LimitObserver.
   void OnAllocationLimitsChanged(uint32_t min_send_bitrate_bps,
                                  uint32_t max_padding_bitrate_bps) override;
 
@@ skipping 1063 matching lines @@
 
 void Call::NotifyBweOfReceivedPacket(const RtpPacketReceived& packet) {
   RTPHeader header;
   packet.GetHeader(&header);
   congestion_controller_->OnReceivedPacket(packet.arrival_time_ms(),
                                            packet.payload_size(), header);
 }
 
 }  // namespace internal
 }  // namespace webrtc